Hi Chanwoo Choi,

On 11/23/18 12:45 AM, Chanwoo Choi wrote:

Hi Lukasz,

On 2018년 11월 22일 19:40, Lukasz Luba wrote:

quoted

Hi Chanwoo Choi

On 11/22/18 3:52 AM, Chanwoo Choi wrote:

quoted

On 2018년 11월 22일 03:01, Lukasz Luba wrote:

quoted

The refactoring is needed for the new client in devfreq: suspend.
To avoid code duplication, move it to the new local function
devfreq_set_target.

The patch draws on Tobias Jakobi's work posted ~2 years ago, who tried to
solve issue with devfreq device's frequency during suspend/resume.
During the discussion on LKML some corner cases and comments appeared
related to the design. This patch address them keeping in mind suggestions
from Chanwoo Choi.

As I commented on patch1, please remove it.

OK

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Suggested-by: Tobias Jakobi <redacted>
Suggested-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Lukasz Luba <redacted>
---
   drivers/devfreq/devfreq.c | 62 ++++++++++++++++++++++++++++-------------------
   1 file changed, 37 insertions(+), 25 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index e20e7e4..cf9c643 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c

@@ -285,6 +285,42 @@ static int devfreq_notify_transition(struct devfreq *devfreq,
   	return 0;
   }
   
+static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
+			      unsigned long *prev_freq, u32 flags)

Please remove the unused space in front of 'unsigned long *prev_freq'.
Use tab only for indentation.

OK

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+{
+	struct devfreq_freqs freqs;
+	unsigned long cur_freq;
+	int err = 0;
+
+	if (devfreq->profile->get_cur_freq)
+		devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq);
+	else
+		cur_freq = devfreq->previous_freq;
+
+	freqs.old = cur_freq;
+	freqs.new = new_freq;
+	devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE);
+
+	err = devfreq->profile->target(devfreq->dev.parent, &new_freq, flags);
+	if (err) {
+		freqs.new = cur_freq;
+		devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
+		return err;
+	}
+
+	freqs.new = new_freq;
+	devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
+
+	if (devfreq_update_status(devfreq, new_freq))
+		dev_err(&devfreq->dev,
+			"Couldn't update frequency transition information.\n");
+
+	devfreq->previous_freq = new_freq;
+	*prev_freq = cur_freq;
+
+	return err;
+}
+
   /* Load monitoring helper functions for governors use */
   
   /**

@@ -296,7 +332,6 @@ static int devfreq_notify_transition(struct devfreq *devfreq,
    */
   int update_devfreq(struct devfreq *devfreq)
   {
-	struct devfreq_freqs freqs;
   	unsigned long freq, cur_freq, min_freq, max_freq;

cur_freq is not used after modification. Remove it.

quoted

   	int err = 0;
   	u32 flags = 0;

@@ -333,31 +368,8 @@ int update_devfreq(struct devfreq *devfreq)
   		flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
   	}
   
-	if (devfreq->profile->get_cur_freq)
-		devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq);
-	else
-		cur_freq = devfreq->previous_freq;
-
-	freqs.old = cur_freq;
-	freqs.new = freq;
-	devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE);
+	return devfreq_set_target(devfreq, freq, &cur_freq, flags);

You get the 'cur_freq' from devfreq_set_taget() for devfreq_suspend_device() on patch3.
But, update_devfreq() and devfreq_resume_device() don't use the 'cur_freq' value
from devfreq_set_target().

Instead, getting 'cur_freq' for 'devfreq->resume_freq' in the devfreq_set_target().
Please remove the 'cur_freq' parameter from devfreq_set_target.

I can remove the 3rd parameter from devfreq_set_target(),
but it implies that patch 1 and 3 cannot be merged. The function
devfreq_set_target will use 'devfreq->resume_freq' so it must be in
devfreq struct.
So, in v2 version there will be still 6 patches, with the 1st patch
defining needed fields in devfreq struct.
Do you agree for that?

So, I replied again as following on my other reply[1] of patch2:
[1] https://lkml.org/lkml/2018/11/22/507

But, you have to add following new code on patch3 instead of patch2.
patch2 doesn't contain the following codes and then
patch3 adds 'resume_freq' variable and adds the following code on patch3.

+
+       if (devfreq->suspend_freq)
+               devfreq->resume_freq = cur_freq;

OK, I will add that change to patch 3.

Regards,
Lukasz

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-	err = devfreq->profile->target(devfreq->dev.parent, &freq, flags);
-	if (err) {
-		freqs.new = cur_freq;
-		devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
-		return err;
-	}
-
-	freqs.new = freq;
-	devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
-
-	if (devfreq_update_status(devfreq, freq))
-		dev_err(&devfreq->dev,
-			"Couldn't update frequency transition information.\n");
-
-	devfreq->previous_freq = freq;
-	return err;
   }
   EXPORT_SYMBOL(update_devfreq);
   

Regards,
Lukasz Luba